By “amphimixis” Weismann meant the union of the two parent germs, which he considered the principal source of heritable variation in evolution by natural selection. English translation in Weismann’s Essays upon Heredity, Vol. 2, Oxford, 1892.

Weismann produced experimental evidence that acquired characters are not transmitted.

Weismann elaborated the theory of the continuity of the germ plasm. English edition, 1893.